Apparatus for handling the electrolytic products of brine in the treatment of fiber.



W. V. WENTWORTH & A. B. LARGHAR. 4 APPARATUS FOR HANDLING THE. ELECTROLYTIC PRODUCTS 0P BRINE IN THE TREATMENT OF FIBER;

APPLIOATIONIILED' JAN. 29, 1907.

912,339. Patented Feb. 16, 1909;

a SHEETS-SHEET 1.

W..V. WENTWORTH &'A. B. LARGHAR.

APPARATUS FOR HANDLING THE ELEGTROLYTIG PRODUCTS 0P BRINE IN THE TREATMENT OF FIBER.

APPLICATION FILED JAN. 29, 1907. 912,339. Patented Feb. 16, 1909.

' 3 SHEETS-SHEET z.

'aml'uan-fou W; v. WENTWORTH & A APPARATUS FOR HANDLING THE ELECTROLYTIC PRODUCTS 01 BRINE IN THE TREATMENT OF FIBER.

LARGHAR.

, APPLICATION FILED JAN. 29, 1907- 4 912,339, Patented Feb. 16, 1909.

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$51 allowing w i/bwwaco UNITED STATES PATENT OFFICE.

WALTER v. wanrwonrn AND issues a. tilt-am, or OLDTOWN, MAINE, ASSIGNQBS. To

.PENOBSOOT CHEMICAL FIBRE GGMPANY, A CORPORATION or MAINE.

' APPARATUS FOR HANDI IIN G TIIE ELECTROLYTIC PRODUCTS OF BRINE IN THE TREATMENT or FIBER.

Specification of Letters Patent.

Application flled' January 29, 1901. semi No. 354,608.

To all whom it may condom: Y o v Be it known that we, WALTER V. WENT- WORTH and An'rnun the United States, and residents of Oldtown, county of Penobscot, State of Maine, have invented a new and useful Improvement in Products of Brine in t Treatment of Fiber,

. Apparatus for- Handring the Electrolytic of which thefollowing we specification.

Heretofore, caustic soda and chlorin produced by electrolysis of brine. (for example, in the cellshown in U. S. Patents to Arthur B. Larchar, patentee,-736,982 dated August 25, 1095, and 793,138 dated June 27, 1905) have been, applied, respectively, to the separation of cellulose fiber frorn wood and. to the bleaching thereof. o

Our present invention constitutes an improved apparatus for handling said electrolytic products between the cell and their points-of application to the fiber.

Inthe accompanying drawings, Figure 1 is a diagrammatic elevation of the apparatus comprised in our system. Figs. 2,3, 4 and 5 are details of the same.

1 and 2 are two electrolytic cells which are referably of the construction shown in said atents; 7 93,138 and 7 36,982. They are supplied with salt brine from the tank 3,

whence it is forced by the pump 4 through the pi e 5 and the branch pipesc and 7 and valve nozzles 8 and 9 to the cells, respecvtively. The chlorin gas product .of the electrolysis leaves the cells through the glazed tile pipe 10 andmust'be combined with lime to form bleach fiber. The caustic soda eifluent leaves the cells by the pipe 11,.which discharges into the storage tank 12. This caustic soda eifluent generally consists of'about cq'upl' parts of caustic soda and unchanged salt in solution, which salt must be separated from the caustic soda before the latter is applied to the fiber.

We-will describe separately the S atoms for handling the caustic soda and the c orin,

respectively, on their way to the iiber.

Handling the caustic soda.Tho combined caustic soda and brine are forced by the pump 13 through the pipe Minto a concentrator 15, which 'isishown in detail in Figs. 4

and 5". This consists of a shell 16 having a,

funnel shaped or hoppenshaped bottom 17. The eta-team tubes 18, slightly inclined B. LABOHAR, citizens of' before it is applied to the from the horizontal, extends across from side to side of the shell 16-, through which tubes steam is circulated between the steam pipes 19 and 20. These steam tubes are so located as to divide the concentrator chamber into the upper vapor space 21 and the sets tling space 22 connected at one side of the bank of tubes by the vertical passage 23.

. hopper 17 and thence circulates up again through the openings in the horizontal pantition 26 among the tubes 18. ,This circula tion continues until the desired concentration is reached and the strength of the circulation combined with the continuous removal of the salt crystals as fast as formed prevent the scaling of the steam tubes. The

valve 27 being open, the concentrated liquon settles into the receiving tank 28 (which is, during this operation, maintained under a vacuum through connection as desired with any suitable means of exhaust, such exhaust not being shown) through the passage 29' at the bottom of the hopper.

The receiving tank 28 consists preferably of a drum rovided near its bottom with a perforated orizontal pipe 30 connected by the pi 31 with a source of compressed'air norms y shut off by the valve 82 (Fig. 1).

33 is the outlet p1 from the rece ver 28,

and 34 the valve t ,erein. This outlet pipe leads to the filter tank 3.5. I

When the liquor in the receiving. tank 28 Patented Feb. 16, 1909.-

has reached-the desired concentration, the

valve 27 is temporarily closed, the valves 3 2 and 34 are opened and the com ressed aublows the contents of the tank t ough the pipe 33 into the filter tank '35. If compressed air is not available, a pump me be used for forcing the li uor from the tan 28 to the-filter tank as. ditional liquor has been pumped mto the concentrator 15 from the tank 12 and con- 11 the meantime, ad-

centrated, the salt crystals partly filling the" hopper so thatas soon as the valve 27 is again opened, the crystals will wash down of sand.

into the tank 28, whereupon the valve 27 is again closed and the receiver 28 emptied as before. In this way, in normal operation, the processbecomes substantially continuous since by opening the valve 27 at frequent intervals, the salt crystals accumulated in the hopper are intermittently withdrawn without stopping the evaporation which is proceedin above. In other words} the salt crysta s accumulate in the downwardly eX-' tending hopper-shaped bottom below the zonelol' evaporation and can be permitted to discharge periodically without interfering with the evaporating process going on in the zone-of evaporation. The salt crystals with entrained caustic soda descending into the vacuum receiver 28, as above described, are in a viscous condition and the air by which they are blown from the vacuum receiver to the filter tank prevents the consolidation of the viscous mass in the receiver 28 because it keeps the mass in a state of agitation as it passes in separate jets from the perforated pi e 30 to the position above the mass whic it mustoccupy for forcing the mass into the bottom outlet 33.

The filter tank 35 contains above its bottom a perforated filter support 36 uppn which is supported a layer 37, 38 prefera ly If the attempt be made'to filter the viscous mass 'of salt crystals and entrained amount of salt is dissolved; while if the partially drained mass of crystals is allowed to cool and'is washed at a temperature low enough to obviate this difiiculty, it is liable to partially congeal so as to prevent the c0mpletion of the operation,

and if pressure be applied to force it through the filter, such pressure will tend to force the finer salt'crystals through with the caustic soda and possibly, also, particles of the filtering material itself. We have made the important CilSCOV- ery, amon others, that these difliculties may 7 tion, we have be avoide I by permitting the mass to cool as a preliminary to filtration. Putting this discovery into use and omitting the pressure,'

but. depenrling-upon-gravity for the filtra found'the operation to be entirely successful; the mass of saltcrystals reuncongealedupon the top :of the filter. Two advantages are thus attained; (1) The cooling causes the separation ofa larger percentage of salt crystals; and "(2) when the salt crystals cool in the caustic solution, they form a loose mass and are much more easily washed.

When; therefore, the filter tank '35.is being filled from the receiving chamber 28, the outletvalves 39, 40 and 41 are closed and repeated.

main so until the mass has hadas muchtime as practicable to cool, when the valve 40 is opened and the concentrated caustic soda allowed to filter. through and drain into the valve 41, by repeated additions of small quantities of cold water from the pipe 46 until the effluent shows the desired freedom from caus-' tic. All of this dilute caustic soda is dis charged through the pipe 43 into the tank 12, whence it again passes through the separator 15. The valve 41 is now closed and the valve 39 opened and the pure salt crystals remaining on the filter are dissolved by additions' of hot water and run into-the brine storage tank 44 from which it is raised by the pump 47 through the pipe 48, into the brine tank 3, whence it is returned with additional brine,

that escaped decomposition at the outset will be returned after being separated from its entrained caustic soda to the cells until it is completely decomposed, while the separated caustic soda accumulated in the tank 42 will be in a condition of purit enabling itto be a plied to the fiber throng the proper channe s. v I p is a tank in which fresh salt crystals are dissolved to make brine and which is connected, respectivel with the pipe 48 and' tank 44 by the valved pipes 81 and 82.

-Handlt'ng' the chZ0rtn.The clilorin gas leaving the cells through the pipelO proce e'ds through the series of absorption towers 51, 52 and 53, each of which is composed of glazed tile. series; the chlorin gas being discharged into the first one at the bottom from the pipe 10, assing thence upward through the tower tower and through the pipel55 down to the bottom of the third tower, thence up through 'These towers are arranged iiiv to the'cells 1', 2 and the operation re- It will thus be seen that all the salt and through the pipe 54 down to the bottom of the next tower, the'nce up through that fresh, most of the chlorin is absorbed in'the first tower but as the proportion of "bleach more chlorin passes onto the second is pumped through the pipe 58 to the tops of the towers. lime tank keeps the lime in suspension while finished chlorid of lime can be increases and that of free lime decreases, tower and toward the end of the operation some chlorin reaches the third tower, but only a trace ever passes through this third tower to the outlet 56, if the apparatus isin proper working order.

59 and "30 are two milk of lime tanks'below the towers.

61 is a concrete trough-into which all of the towers discharge their liquid chlorid of lime at the bottom and-from which trough such liquid may be discharged either into the tank 59 through the pipe 62, or into the tank 60 through the pipe 63; the pipe not inuse being closed by a suitable plug 6-1. Valved outlet-pipes 65 and 66 lead from the bottom of each milk of lime tank o the pump 67 by which the milkof lime from the tank in use An ag1tator'68 in each milk of l it is in operation. Each milk of lime tank is provided with a pivoted stand-pipe 69 connected with a valved outlet pipe 70 and controlled by a cord 71 so that the bleach or drawn ofi from depth desired. This proper condition to be aplied through suitable channels to the bleaching of the wood fiber. s

In Big. 2 is shown a detail of the dashplate 58 and the lime-inlet-pipe 58 in one of the towers.

In Fig. 3, is shown a detail of the bottom of one of the towers and the chlorin-inletpipe 10 and'of the liquid-outlet-pipe 61 into the concrete trough 61.

In operation, one of the milk of limetanks will be filled with milk of lime which will be circulated by the pump 67, over and over, through the absorption towers 51, 52, 53, I until it is all converted substantially into I bleach. In the meantime, the other the tank to any bleach is in caustic soda is se tank 60 Waite filled with milk of-lime so that as soon as the conversion in the tank- 59 is complete, it can be cut off from the tow- From the foregoing description, it will be seen that the whole system, inclusive of that portion for handling the caustic soda, as Well as-that portion for handling the chlorin is substantially continuous, enabling the cells, the absorptiontowers and the concentrator 15' to be in substantially tion and yielding a substantially continuous supply of both bleach and caustic soda to the fiber treating operations of a paper pulp mill.

Having thus described our invention, we claim as new and desire to secure by Letters Patent: x

1. In combination, a cell for the electrolysis of brine, an evaporator wherein the caustic soda efiluent is coi'icentratcd, a receiving chamber means for discharging the concentrates thereinto without intermitting the evaporation, and a filter tank wherein the parated from the salt.

2. In combination, a cell for the electrolysis of brine, an evaporator for the caustic soda eflluent containing below the zone of evaporation a pocket for the settling of the concentrates, a vacuum chamber into which said pocket discharges, a filter tank and means whereby concentrates are forced from said vacuum chamber to said filter tank In testimony whereof, we have hereunto signed our names in-the presence of two subscribing witnesses.

WALTER V. WENTVVORTH ARTHUR B. LARCHAR. Witnesses: Jos. F. GOULD, CLARA H. GOULD.

continuous opera-' the absorption towers will be in 

